Internal-combustion heat-engine.



No. 808,336. PATENTED DEC. 26, 1905.

J. L. BOGERT.

INTERNAL COMBUSTION HEAT ENGINE.

APPLICATION FILED OCT. 26, 1904.

4 SHEETS-SHEET 1.

No. 808,336 PATENTED DEC. 26, 1905. J. L. BOGERT. INTERNAL COMBUSTIONHEAT ENGINE.

APPLICATION FILED OCT. 28, 1904.

4 SHEETS-SHEET 2.

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J. L. BOGERT.

INTERNAL COMBUSTION HEAT ENGINE.

APPLICATION FILED 001'. 26, 1904.

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APPLICATION FILED 0GT.26,190-4- 4 SHEETS-SHEET 4.

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INTERNAL-COMBUSTION HEAT-ENGINE.

Specification of Letters Patent.

Patented Dec. 26, 1905.

Application filed October 26,1904. Serial No. 230,017.

To ctZZ whom it may concern.-

Be it known that 1, JOHN L. BOGERT, a citizen of the United States,residing in New York city, borough of Queens, State of New York, haveinvented certain new and useful Improvements in Internal-CombustionHeat-Engines, of which the following is a specification.

My invention relates to improvements in the class of internal-combustionheat-engines in which a charge of combustible and air is compressedbefore ignition.

As theoretically the greatest economy in fuel consumption and themaximum power per volume of working cylinder are obtainable by employingthe highest possible compression at the point of ignition, which latteris supposed to take place at the inner dead-point when a reciprocatingpiston is employed, an unchangeable compression-space is deficient,because a mixture rich in fuel or containing little surplus air-will notpermit the same degree of compression as a poor mixture or onecontaining a large surplus of air over fuel. Again, when the walls ofthe cylinder are cold a higher compression is possible than when hotfrom the effects of repeated explosions, and hence an engine that isrunning light or cutting out explosions could employ a higher degree ofcompression than a heavily-loaded one. Furthermore, the nature of thefuel used also determines the amount of compres sion possible to beobtained, for, as a rule, gaseous fuels permit much higher compressionsthan liquid or vaporous ones.

The object, therefore, of my invention is to provide means for varyingthe compression of the combustible mixture in internal-combustionheat-engines at the will of the operator, whereby advantages hereinafterpointed out may be obtained.

As the majority of internal-combustion heat-engines now used make use ofthe Beau de Rochas cycle, I have shown in the accompanying drawingsdevices that may be employed in the construction of four-cycle gas oroil engines; but it will be understood that other cycles employingcompression-pressure prior to ignition or inflammation may be used inconjunction with my improvements. Such type of engine is largelyemployed in automobiles and autoboats, in which engines the speed ofrotation of the driving-shaft is commonly high to insure great power fora given weight, often a double stroke of the powerpiston occupying but atwentieth of a second. Now as a sensible amount of time is required forthe propagation of the flame it is customary to advance the spark as thespeed of piston reciprocation increases more and more until ignition ofthe charge takes place considerably before the piston has reached itsinner dead-point. For this reason the pressure of compression isconsiderably lower when the spark passes between the terminals than itwould be if ignition took place at the exact dead-point, and as thoroughinflammation of the charge is more rapid in proportion to thecompression produced by reducing the compression-space as the speedincreases the best results may be obtained. Also when the admission ofthe fuel mixture is throttled a smaller compression-space may beemployed, because the quantity of mixture to be compressed is muchsmaller, and when starting an engine by hand if the compression-space isrelatively small it is diflicult to force the piston against theresulting pressure of compression. Hence an increase in the size of thecompression-space because of the decreased resulting pressure ofcompression would facilitate the.starting of the engine. Myimprovements, therefore, are designed to effect the advantagescomprehended in the foregoing, and to this end I provide an adjustablepiston in a space or chamber that is in communication with thecompression-space of the main driving-piston, whereby the effectivecompression-space is variable at will.

Reference is to be had to the accompanying drawings, forming parthereof, wherein Figure 1 is a vertical section of a well-known type ofvertical internal-combustion heat-engine provided with my improvements.Fig. 2 is a plan view of Fig. 1. Fig. 3 is a horizontal section on theline 3 3 in Fig. 1. Fig. 4 is a plan View showing means forsimultaneously varying the compression-spaces of a plurality ofcylinders in an engine. Fig. 5 is a vertical section showing means forcooling and operating the variable-compression piston. Fig. 6 is avertical section through the cylinder and vaporizer of a horizontalengine of the well-known Hornsby-Akroyd type provided with myimprovements, and Fig. '7 is a central section of an engine in which twocylinders are employed to utilize the force of the expanding gases.

Similar numerals of reference indicate corresponding parts in theseveral views.

In the drawings the numeral 1 indicates an engine-cylinder; 2, thepower-producing piston; 3, the crank-shaft, having cranks which in Fig.1 are shown formed like fly-wheels 4:, 5 being the connecting-rodbetween the piston and crank, 6 the fuel-intake valve, 7 theexhaust-valve, and 8 the mechanism for operating the exhaust-valve fromthe drivingshaft 3, and 9 a spark-plug incommunication with thecompression-space. As all of the foregoing parts are usual ininternal-combustion heat-engines, they need no further description andmay be of any desired form and construction.

At 10 is indicated my variable-compression piston, shown in Figs. 1, 5,and 7 as lo cated within a prolongation 1" of the cylinder 1 in linewith the piston 2, the chamber 1 thus formed being in communication withthe compression-space 11, that communicates, through port 11?, with theintake and exhaust valves 6 7. The variable-compression piston 10 isshown provided with usual packing-rings and is caused to be adjustedwithin its chamber 1 toward and from piston 2 by means of rod 12. Thesaid rod 12 is shown passing through a stuffing-box 13 and gland 13 inthe cylinder-head 13, said rod being shown threaded for a portion of itslength at 12, the threads meshing with a nut 14, carried by a support 15on the cylinder-head, a handwheel or the like 16 being keyed fast to theupper end of rod 12. \Vhen the power-piston 2 advances on thesuction-stroke, the mixture of air and fuel is drawn past the airvalve 6through port 11 into compressionspace 11 and follows the outward motionof the piston, thus filling the working volume of the cylinder 1, andthe return stroke of the piston compresses this charge within the spacebetween the inner face of the powerproducing piston 2 and the opposedinner face of the Variable-compression piston 10, the port 11 being atthe same time filled with a portion of this more or less highlycompressed mixture, and when a spark is passed between the innerterminals of the igniter 9 the ignition of the fuel and air takes place,the pressure within the compression-space rapidly rising and thepower-stroke of the piston ensuing. It will now be evident that byscrewing inwardly the variable-compression piston 10 more or less towardthe power-producing piston 2 the compression-space will beproportionately reduced in volume, and hence the compression-pressurewill be raised, and likewise by adjusting the variable-compressionpiston 2 outwardly or away from piston 2 the compression-space will beincreased in volume, and hence the compression-pressure will be reduced.By means of said variable-compression piston 10 the volume of thecompression-space may be so adjusted that the fuel mixture will explodewhen the inner deadpoint of the piston 2 is reached even if the sparkerfails to operate, and especially is this the case if one or moremetallic projections are interposed into the compression-space,

tance within chamber 1.

such as indicated at 17. In this class of en gines it frequently occursthat where the load on the engine is heavy and explosions are takingplace every second outstroke of the piston there is such an accumulationof heat that premature ignition takes place, and the charge is ignitedtoo soon. By varying the compression-space by means of piston 10 andcutting out explosions the temperature may be reduced. It will thus beunderstood that by means of the variable-compression piston 10 thevolume of the compression-space for the explosive mixture may be readilyvaried at will, whereby to regulate the power and speed of the engine,thereby enabling the operator to utilize the advantage of the highestcompression-pressure or a relatively low compression-pressure, as may bedesired and in accordance with the work to be done. By adjusting thepiston so that the compression causes the fuel mixture to explodespontaneously when the compression-pressure reaches the highestpointpossible, whereby to produce explosion or inflam mation,the ignitiondevices need not then be depended upon, and likewise by greatlyincreasing the compression-space by moving the piston 10 away frompiston 2 starting of the engine can be accomplished with greater easeand less powerful explosions will result, and between these two limitsany desired degree of compression may be obtained by correspondinglyadjusting piston 10 toward or from piston 2.

Where it is desired, water-jacketing may be applied to thevariable-compression piston 10. An arrangementfor this purpose is shownin Fig. 5, wherein two hollow or tubular piston-rods 12 are used andwhich communicate with a water-space 10 in piston 10, the outer ends ofwhich tubular or hollow rods may be connected with the water-circulatingsystem of the engine by flexible hose to permit adjustment of piston 10.The stufiing box, glands, and nuts are shown made in duplicate to accordwith the two hollow piston-rods 12, and I have shown one piston-rod 12provided with right-hand threads and the other with left-hand threads,said rods being fixed to the piston 10. In this case the nuts 14 retatein bearings in the yoke or support 15, and to said nuts are securedworm-wheels 18, that mesh with a common worm 19, which is keyed to shaft16 to be rotated by hand-wheel 16, all in any suitable manner, (wheel 16not being shown in Fig. 5.) Thus when shaft 20 is rotated the two rodswill be simultaneously moved to adjust piston 10 to the desired dis- InFig. 5 the metallic projection 17 is shown attached to piston 2. Themetallic projection 17 serves as an igniter when hot, but tends to limitthe amount of compression possible with some fuels, as such projectionattains a higher temperature than the walls of the compression space.

As multicylinder engines are extensively used, I have in Fig. 1 shownmeans for simultaneously varying or altering the compression-space of anumber of cylinders. In this figure I have shown engines with doublevalve-ports, the exhaust-valves being on one side and the air and fuelvalves on the other; but my improvements are applicable to any knowntype of engine of the class described. In said figure the hand-wheelshaft 16 is shown provided with worms 19, meshing with wormwheels 18,secured to shafts 12 in manner similar to Fig. 5, which cause thepiston-rods 12 and their variable-compression pistons 10 to move up ordown to an equal extent at the will of the operator. If desired, in anautomobile the same handle or hand-wheel may be employed to advance thespark and operate the rod or rods 12 of the piston or pistons 10 toalter the compression in the cylinder or cylinders simultaneously,though preferably these adjustments should be separate.

From the foregoing description it will be understood that myimprovements may be applied to a gas or oil engine of any wellknownconstruction wherein the end of a cylinder is not utilized as avalve-case or a vaporizer without material alteration in design. Inengines employing the end of the cylinder for supporting or containingvalve-case or vaporizer or spark-plug it will be obvious that they maybe placed to one side of the cylinder end to accommodate the piston 10,

' or the piston 10 may be placed in a chamber at one side of andcommunicating with cylinder 1, so as not to disturb the position of thevalves, vaporizer, and ignition devices. Such an arrangement isillustrated in Fig. 6, and in this particular illustration I have shownmy improvements adapted to that large class of engines in which for somereasons it is important that the cylinder-head should be employed foranother purpose. For this example I have illustrated the well-known typeof engine of which the Hornsby-Akroyd is a representative,because theprincipal difliculty with this type of engine is most effectively curedby means of my improvements. In said figure the chamber 1 is formed onone side of cylinder 1 and may be water-jacketed, and said chambercommunicates by a port 11 with the compression-space 11, the port 11communicating with the exhaust and inlet valves. In this case theconstricted passage 11 opens through the cylinder-head 13 from thecompression-space 11 into the vaporizer 11, whose walls'are keptconstantly hot at starting by means of the lamp or the like andafterward by the action of the internal combustion, the oil being pumpedinto the vaporizer 11 through the inlet 11", the design being to keepthe Walls of the vaporizer not too hot, but just hot enough to fire thecharge at the inner dead-point of the driving-piston 2, the liquid fuelbeing pumped into the vaporizer in just the proper quantity throughinlet 11 This engine gives excellent results when the load does not varymuch; but if it is overloaded the walls of the chamber 11 get hotter andhotter until prematureignition takes place and the engine stops, or ifthe load is reduced greatly the infrequency of the explosions or thereduced richness of the mixture permits cooling down of the walls belowthe temperature at which ignition will take place. Itwill therefore bereadily understood that if the compression-space 11 or any spacescommunicating with it are varied in volume more or less air will beforced into the vaporizer 11 before the inner end of the stroke of thepiston 2 is reached, also that the temperature will rise with thecompression. Therefore by means of my improved variable-compressionpiston 10 the quantity of air that may be forced into the vaporizer 11on the compressionstroke of piston 2 may be varied to meet theconditions arising under changes of load and otherwise to cause the moreconstant proper explosions to occur more regularly, whereby to preventpremature ignition from taking place and also to prevent cooling down ofthe walls of the vaporizer below the temperature required to produceignition of the charge. It will thus be understood that any mechanicalmeans for increasing or decreasing at will, while the engine operates,the volume of the compression-space other than by the reciprocatingmotion of the power-producing piston or pistonsis within the scope of myinvention and that the variable-compression piston 10 may take the formof aplunger acting by displacement in manner Well known in plungerpumpsfor liquids. Again, the bore or the chamber 1 in which thevariable-compression piston or plunger 10 is adjusted may radiate outfrom the compression-space 11 in any desired direction. Where asinglepiston-rod 12 is used and the piston 10 is circular, if the nut 1 1 isrotated it will be necessary to prevent the turning of the piston-rod12. In Fig. 6 I have shown means for this purpose in which the rod issplined and a key or feather 20 is set in one side of the bore of acasting 21, attached to the cylinder, which fits over the prolongationof rod 12, whereby it can slide freely without rotating. In this casethe nut 14 and worm-wheel 18 may bemade in a single piece and arejournaled in split bearings 22, supported by the cylinder, and the shaft16 of hand-wheel 16 and its worm 19, that meshes with worm 18, may bejournaled in bearings on a bracket 15, carried by the maincylindercasting 1. Thus when wheel 16 is rotated piston 10 may beadjusted at the desired amount.

It is comparatively easy to obtain self-ignition with most mixtures ofhydrocarbon vapors and air; but with the permanent hydrocarbon gases, socalled, such as ordinary coalgas, very high compression-pressures may beobtained, and there are some mixtures of fuelgases and air that requirecompression-pressure of over two hundred pounds per square inch toenable the electric spark to produce rapid inflammation. Excessivepressure of compression in ordinary gas-engines or oilengines (whereobtainable) produce very high pressures,necessitating great strength ofparts and rapid wear from piston leaks. In Fig. 7 1 have shown how themaximum amount of compression possible to be obtained in aninternal-combustion engine with any given fuel mixture may be utilizedwithout exceeding a substantially predetermined explosion-pressure. Insaid figure two power-producing pistons 2 2, which may be of differentdiameters, are shown in two cylinders 1 1 shown cast together andcommunicating by means of ports and passages 11 11 controlled by aninterposed valve 22. Said valve has its upper face enlarged to formaquieting-piston and rises and falls in the socket 23 of its guide orcase 24:, shown held by the cover 13 in a bore in a cylinder-casting.Small grooves in the edge of the upper portion of piston 22 permit thepres sure in 23 to vary with the pressure in passage 11' while the valveis seated, and so soon as the valve lifts these grooves cannot longer soact. The power-producing pistons 2 2 and their connected parts aresimilar, differing onlyin dimensions according to the difference in thebores of the two cylinders. The connecting-rods 5 may be o the samelength and connect the pistons with their respective crank-pins 3" ofshaft 3; but said crank-pins are offset or located at any suitable anglewith respect to each other-say at an angle of fortyfive degrees-asindicated diagrammatically in dotted lines in Fig. 7. By observing thedirection of the arrows in said figure it will be seen that the largerpiston leads the smaller by an amount which may be anything and which isillustrated to be substantially fortyfive degrees. In Fig. 7 the largerpiston is shown at its extreme inner dead-point, while the smallerpiston has yet a considerable distance to move before reaching its innerdeadpoint. At 25 is an air-intake valve communicating with a passage 26,leading to cylinder 1 and 7 indicates the exhaust-valve, all of whichmay be constructed and operated in any well-known manner, valve 25communieating with the atmosphere only, so that the larger piston drawsin and compresses air only, while the smaller piston draws in andcompresses a mixture of fuel and air in manner described with respect toFig. 1. Above the smaller piston 2, and adjustable up and down in thebore 1*, is shown the variable-compression piston 10, fully describedhereinabove. If now said compression-piston 10 be screwed downsufficiently to cause explosion at the proper degree of compression ofthe fuel and air mixture in the smaller or firing cylinder 1, the suddenrise in pressure will be suflicient to lift valve 22, and thereby aportion of the burning mixture will pass over into the compressed airbehind the larger piston 2, thereby producing increased pressure behindthe larger piston. By properly proportioning the relative diameters ofthe larger and smaller pistons the explosion-pressure may be kept withindesired limits, although the compression-pressure is very high. Theobject of setting the crank of the large cylinder forward or in advanceof the crank of the smaller cylinder is to permit a certain amount ofpremature ignition in the small cylinder without liability to stop theengine. For reasons set forth above if the variable-compression pistonis adjusted to insure spontaneous explosion with a light load on theengine at the inner dead-point of the small piston when the engine isincreasingly loaded the spontaneous ignition will take place more andmore in adance of the inner dead-point of the small piston, and it isdesirable to have the crank of the larger piston advanced far enoughahead of the smaller-piston crank to insure always enough positiveturning force by reason of the pressure in the large cylinder toovercome the negative turning force in the smaller cylinder due topremature ignition. The operator by screwing in or out thevariable-compression piston 10 can always keep this variation of time ofignition within desired limits.

As the valves 6 and 25 may be operated by the suction of theirrespective pistons or in any well-known manner and'as the exhaustvalves7 may be operated by any well-known devices or as shown in Fig. 1, Ihave not in Fig. 7 illustrated means for the purpose, as I do not limitmyself to any particular arrangement of valves. Furthermore, the liquidfuel or a portion thereof may be ignited into the compression-space ofthe smaller cylinder by a pipe leading into the same, as at 26.

An engine constructed in accordance with Fig. 7 may be used as acompression, gas, or oil engine, whether of the four-cycle or twocycletype, and said construction overcomes the difficulties found by reasonof the high pressure required in the well-known Diesel motor.

My invention is not limited to the details of construction shown anddescribed, as the same may be varied without departing from the spiritthereof.

Having now described my invention, what I claim is 1. Aninternal-combustion heat-engine comprising two cylinders, one being afiring-cylinder and both provided with compressionspaces thatcommunicate by a passage, a checkvalve in the passage opening away fromthe firing-cylinder, pistons in said cylinders, and a shaft havingcranks respectively connected with said pistons, one of said cranksbeing located in advance of the other so that one of the pistons willhave passed its inner deadpoint at the moment of ignition of a chargecompressed by the other piston, substantially as described.

2. An internal-combustion heat-engine comprising two cylinders one beinga firing-cylinder and both provided with compressionspaces thatcommunicate by a passage, a checkvalve in the passage opening away fromthe firing-cylinder, pistons in said cylinders, a shaft having cranksrespectively connected with said pistons, one of said cranks beinglocated in advance of the other so that one of the pistons will havepassed its inner dead-point at the moment of ignition of a chargecompressed by the other piston, and means for varying the volume of thecompression-space of the fuel and air cylinder at will during operation,substantially as described.

3. An internal-combustion heat-engine comscribed.

JOHN L. BOGERT. Witnesses:

T. F. BOURNE,

M. HOLLINGSHEAD.

